Increase the default DATA_EXPAND_SIZE to max(8 GiB, current_dirty_mem)
Increase the default DATA_EXPAND_SIZE to max(8 GiB, current_dirty_mem)

To keep ahead of data consumption from the pool - make the expansion of
the data device larger.

Signed-off-by: Todd Gill <7afbb5ba98932b8ffb9cc9e6675c4792db142529@redhat.com>

stratis-storage/stratisd,mulkieran/stratisd,trgill/stratisd,stratis-storage/stratisd,mulkieran/stratisd,stratis-storage/stratisd,trgill/stratisd